APPLICANT'S ABSTRACT: The goal of this two-year project is to examine the temporal relationship between life stress and alcohol use as it unfolds in the everyday lives of college students, and the role that psychosocial protective and vulnerability factors may play in moderating this relationship. A number of studies have documented positive relationships between increased life stress or distress and increased alcohol consumption in college students; however, no study to date has examined relations between daily fluctuations in stress and alcohol consumption among college student. The methodology used in this study, daily diary reports, represents a major advance in research on stress and alcohol use: Daily reporting of stress and alcohol consumption and the application of multilevel modeling reduces recall distortion and allows for the simultaneous examination of the within-by-between-person question of whether certain individuals drink more on high stress days versus low stress days. Three-hundred college students will complete measures of psychosocial protective and vulnerability factors. Then, for 21 days, they will record in structured diaries their daily stress, coping, and mood, and previous night's stress and alcohol consumption. Multilevel regression analyses will be used to address the following questions: (a) Do students drink more alcohol during high stress periods (days, weeks) compared to low stress periods?; (b) Do negative mood states and emotion-focused coping, efforts mediate the effects of stress on alcohol consumption?; and (c) do college students with fewer psychosocial resources and greater vulnerability markers, compared to others, drink more during high stress periods (days, weeks) versus low stress periods, and are these associations the same for men and women? Answers to these questions might guide intervention efforts aimed at reducing problem drinking patterns and their long term consequences.